Mechanisms that Underlie Experience-dependent Assembly of Neural Circuits.

Abstract

I aim to understand the interaction between the environment and the developing brain through investigating how sensory experience shapes behavior. Sensory experience modifies neural connections through activity-dependent plasticity, enabling animals to cope with environmental variability. Classic work, particularly those in vertebrate visual systems, has provided important insights into the mechanisms that underlie experience-dependent plasticity of the developing circuit. However, there are significant gaps explaining the mechanism by which sensory experience shapes circuit function during development. This dissertation examines how sensory experience during development changes the sensorimotor circuit to shape behavior in Drosophila melanogaster. Drosophila provides a relatively simple and genetically amenable model for analyzing both neural development and mechanisms underlying behaviors, and is thus a powerful model for discovering basic principles underlying experience-dependent plasticity during development. To address how sensory stimuli alters the sensorimotor circuit, I have established a calcium live-imaging technique to physiologically measure neural dynamics within larval brains and have developed a behavioral assay to probe motor output. Through the use of these experimental techniques, I have determined that sensory experience during a sensitive period in development modifies behavior through an intrinsic program of circuit development. These findings suggest that the development of the larval sensorimotor circuit is shaped by sensory input and neural activity.